1. Field of the Invention
The invention relates to novel oil-soluble amine salts of partial esters derived from the reaction of organic acid materials such as dicarboxylic acids or anhydrides and an aldehyde/tris-(hydroxymethyl) aminomethane adduct or mixture. These novel oil-soluble amine salts have utility as additives for hydrocarbon fuels including gasoline.
2. Description of Prior and Related Art
Lubricant and fuel additives derived from hydrocarbon substituted succinic anhydride, e.g., polyisobutenylsuccinic anhydride, with compounds containing both an amine group and a hydroxy group have been suggested or investigated in the prior art. The art also teaches useful lubricating oil detergents of the Schiff base type are prepared by reacting alkenylsuccinic acid anhydride and a polyamine to provide an imide intermediate subsequently reacted with an aldehyde (see U.S. Pat. No. 3,455,831). United Kingdom Specification No. 809,001 teaches corrosion inhibitors comprising a multiple salt complex derived from the reaction product of hydrocarbyl substituted dicarboxylic acids and hydroxy amines (including 2-amino-2-methyl-1,3-propane-diol [AMP] and tris hydroxy methylaminomethane (hereafter designated THAM) further complexed with mono- and polycarboxylic acids.
U.S. Pat. No. 3,632,511 teaches reacting polyisobutenylsuccinic anhydride with both a polyamine and a polyhydric alcohol including THAM. United Kingdom Specification No. 984,409 teaches ashless, amide/imide/ester type lubricant additives prepared by reacting an alkenylsuccinic anhydride, with a hydroxy amine including THAM.
In British Pat. No. 564,506, the condensation product of THAM and formaldehyde, i.e. 1-aza-3,7-dioxabicyclo[3.3.0]oct-5-yl methyl alcohols is said to react with fatty acids to give unstable ester products which are useful as drying oils.
In contrast to the above disclosures, we have found that carboxylic acids or anhydrides can be treated with an aldehyde-THAM adduct or mixture to give novel amine salt compositions particularly useful as an antirust additive for liquid hydrocarbon fuels.